A technician cleans and carries out maintenance work on one of the faces of the Great Clock atop the landmark Elizabeth Tower that houses Big Ben, attached to the Houses of Parliament, in London, on Tuesday. Photo: AFP/BEN STANSALL

London: Wearing ear plugs to muffle the chimes of Big Ben, a team of abseilers is busy this week cleaning the clock faces at the Houses of Parliament in London.

Wearing hard hats and armed with buckets and cloths, the four specialist technicians are descending the London landmark by rope to clean and inspect the four clock faces.

The clock faces on the Elizabeth Tower were last cleaned in 2010 and besides getting rid of any dirt that has accumulated since then, the experts are conducting a photographic survey to check the dials for damage.

"Big Ben is one of the UK's greatest icons, and cleaning the Great Clock is a vital part of its maintenance," said Steve Jaggs, deputy keeper of the clock.

"The process is complex and requires a real head for heights. We have an expert team who will ensure that the clock is thoroughly cleaned and that this piece of our national heritage is safeguarded for future generations."